Derrick leg footing



July 4, 1939. DE 2,164,428

DERRICK LEG FOOTING Filed July 29, 1938 Patented July 4, 1939 g V UNITED STATES PATENT OFFICE DERRICK LEG FOOTING Aaron D. Rhodes, Los Angelcs, Calif., assignor to Consolidated Steel Corp, Ltd., Los Angeles, Calif., a ocrporaticn of California Application July 29, 1938, Serial No. 221.947

Claims. (Cl. 189-21) My invention relates to the construction of derin the shops, thus eliminating the relatively exrick towers and has particular reference to a pensive operation of fitting and attaching at the derrick leg footing. erection site. 7

A derrick is used in the well drilling industry It is an additional object of my invention to for handling the equipment for drilling the well, provide a derrick leg footing of a design which 5 and in the case of deep Wells, such as oil or gas will allow the formation of said footing and the wells, is called upon to support a load of many lower portion of the derrick leg integrally with tons. This load gives rise to very great stresses each other. in the derrick leg foundation, with the result that Other objects and advantages of my invention 10 it is not unusual for a foundation to settle and will become apparent from a consideration of the throw a derrick out of vertical alignment. It following description of the preferred embodithen becomes necessary to jack up and shim ment of my invention, taken in connection with under one or more legs to re-establish the vertical the accompanying drawing, in which: alignment. Fig. l is a plan View of a portion of a derrick Many schemes have been devised to provide a foundation showing the derrick leg footing of my 1 means for attaching the derrick leg to the foundainvention in connection with the lower portion tion and make provision for jacking up the leg, of a derrick leg and the derrick base ties and but all have many disadvantages. Certain dissupports secured thereto.

advantages, however, are common to most of the Fig. 2 is a side elevation of the derrickand leg present derrick leg footings. For example, the footing shown in Fig. 1. 20 footing members are usually attached to the der- As shown in Figs. 1 and 2, the base corner rick leg by means of bolts, with the result that of a conventional derrick of this class includes all of the load on the leg must eventually, if not a foundation pier 3, usually of concrete or other initially, be carried in shear in the bolts. This suitable material, upon which is placed a foundarequires a number of very large bolts, with the tion leveling plate which in turn usually sup- 25 result that the holes therefor in the leg seriously ports the derrick leg 5. Perimetric members 6. impair the bending strength of the leg. Devices usually of channel form, and diagonal braces l of this type are also relatively expensive to install, are also employed. In order that the derrick may inasmuch as all holes must either be drilled in the operate as a unit structure for supporting the field at great cost or drilled in the shop with a great loads which are applied, it is necessary 30 great deal of clearance to assure a fit in the field that all of the aforementioned parts be securely and results in a possible serious impairment of attached to each other. In the present invention the strength of the parts. this is accomplished with my novel derrick leg Derrick leg footings at present employed also footing in the following manner.

5 have a disadvantage in that the lifting force of Footing side plates 8 are securely attached to, the jack which is used to lift the derrick leg must as by welding, or formed integrally with the derbe transmitted from the footing membersto the rick leg 5 and are allowed to extend beyond the leg through some connecting means, usually bolts. edges of the leg to permit attachment of the It is therefore an object of my invention to perimetric members 6 as by bolts or other suitable provide a derrick leg and footing assembly in fastenings El. 40 which the footing and leg are formed together as Inasmuch as the derrick leg 5 does not extend an integral unit. vertically but slopes inward toward the center Another object of my invention is to provide a of the derrick tower and inasmuch as the asderrick leg footing in which the jack clip forming sembly of floor joists and other structural mem- 5 a part thereof is attached to the derrick leg in bers of the derrick base is facilitated if the sides such a manner as to in no way impair the strength of the perimetric members 5 are vertical, I have of either the footing member or the derrick leg. provided a slight twist in the footing side plates It is also an object of my invention to provide 3 so that one portion lies parallel to the derrick a derrick leg footing of such type that said footleg 5 and the extending portion lies parallel to ing may be attached to the derrick leg without the vertical side ofthe perimetric member 6. I 50 weakening the footing or the leg. In order to securely attach the diagonal brace Another object of my invention is the pro- 1 to the base corner unit I have provided a division of a derrick leg footing of such design that agonal brace clip l9 which is secured to the footthe footing may be permanently and securely ating side plates 8 as by welding, or which may be tached to. the lower end of the derrick leg while attached thereto by the same bolts 9. employed to 55 connect the perimetric base channels 6 to the side plates. The clip In extends between the projecting ends of the side plates 8 and behind the derrick leg 5. I have made the brace clip H! of such shape that the central portion thereof provides a flat surface against which an attachment plate Ta, welded upon the end of the diagonal brace 7, may abut and may be secured thereto as by bolts II.

I have provided a footing plate l2 for the purpose of adapting the previously described unit assembly for resting on the foundation leveling plate 4. This footing plate l2 may be of almost any shape desired, but the form illustrated in Fig. 1 is preferred for reasons to be set forth hereinafter. The footing plate I 2 is securely attached to, as by welding, or is formed integrally with the derrick leg 5 and the footing side plates 8. The entire unit is then attached to the foundation as by bolts l3 and nuts l3a embedded in the foundation 3 and extending upwardly through suitable holes in the plates 4 and I2.

While the advantages of this type of derrick legging in its inherent simplicity, strength and rigidity have been outlined, the economies in manufacture resulting from this type of construction should not be overlooked. With this type of construction, the lower portion of the derrick leg and the parts forming the footing may be fabricated in the shop to very close tolerances through the use of jigs, templates, and similar methods. While this same procedure may be used in the field, the accuracy of fabrication is in question and the cost many times that of shopfabrication.

Should it be desired for any reason to raise one or more corners of the derrick, such adjustment is readily accomplished by raising the entire leg and leg footing and inserting shims of the proper thickness between the footing bottom plate 52 and the leveling plate 4.

In order to provide means for lifting the derrick leg after the derrick is erected, for the reasons outlined hereinbefore, I have provided a jack clip l4 securely attached to or formed integrally with the derrick leg 5.

The jack clip I may be of any shape desired, but as illustrated is constructed in the form of a V shaped plate with the derrick leg angle 5 lying inside the V and the apex of the V extending an appreciable distance from the corner of the leg. I propose to place the jack clip [4 the proper distance above the foundation plate 4 to allow a toejack resting thereon to be used to raise the leg by engaging the toe of the jack with the under surface of the jack clip I4. As best shown in Fig. 1, I prefer to cut off that corner of the footing plate I2 which lies below the jack clip I4 to leave a clear space IS on the foundation plate 4 for accommodating the toe jack as indicated in dotted lines I6 in Fig. 2.

I have therefore provided a new and novel derrick leg footing which eliminates many of the disadvantages existing in the current methods of construction and which will allow an appreciable reduction in the cost of fabrication and erection of derricks of this class. The construction I have described provides astronger and more durable unit than any now available and will therefore reduce the cost of maintaining this class of derrick through the elimination of failures and excessive strains at this point.

In actual practice the employment of my derrick leg footing formed as a unit with the leg angle 5 facilitates the erection of the derrick in the field by permitting the assembly on the ground of a complete section or panel representing the lower portion of one side of the derrick including a pair of adjacent legs and the girts and braces extending therebetween. Such assembly may then be lifted in place and set upon the foundation piers with the footing bottom plates l2 resting in place upon the attachment bolts l3. The nuts l3a may then be quickly screwed down and that portion of the derrick side will be supported solely by the bolts !3. This will permit the disconnection of the machinery employed to lift the assembled section in place and permit it to be used for lifting a section of the opposite side of the derrick into place.

When the bolts l3 for that side of the derrick are tightened, the erection machinery may then be disconnected and used to place the girt and bracing panels for the other two sides of the derrick, while the first two side sections are held and supported solely by the bolts I3. This is permitted with my derrick leg and footing assembly by reason of the fact that all of the strains are transmitted directly between the derrick leg and the footing plates without exerting shearing stresses upon a few bolts as is the case with separate footings merely bolted to the derrick legs.

Although I have illustrated and described a preferred embodiment of my invention, it is to be understood that changes in the details of construction and arrangement of parts may be made without departing from the spirit of the invention, and I do not wish to be limited except as defined in the appended claims.

I claim:

1. As an article of manufacture, an integral derrick leg unit comprising: a derrick leg portion terminating at one end in a footing plate integral with said leg portion and disposed transversely thereof; and a bracing plate integral with said leg portion and said footing plate for bracing the junction between said leg portion and said footing plate.

2. As an article of manufacture, an integral derrick leg unit comprising: a derrick leg portion terminating at one end in a footing plate welded to said leg portion as an integral unit therewith and disposed transversely thereof; and a bracing plate for bracing the junction between said leg portion and said footing plate, said bracing plate being welded to said leg portion and to said footing plate to form an integral unit therewith.

3. As an article of manufacture, an integral derrick leg unit comprising: a derrick leg portion terminating at one end in a footing plate integral with said leg portion and disposed transversely thereof; and a plurality of bracing plates integral with said leg portion and said footing plate and disposed at angles relative to each other for bracing in a plurality of directions the junction between said leg portion and said footing plate.

4. As an article of manufacture, an integral derrick leg unit comprising: a derrick leg portion having an L shaped cross-section and terminating at one end in a footing plate integral with said leg portion and disposed at such an angle to said leg portion as to place said footing plate in a substantially horizontal position to act as a footing member for said leg portion when said leg portion is installed on a derrick; and a pair of bracing plates integral with said leg portion and said footing plate, each of said bracing plates lying substantially in the plane of one of the arms of said L shape for bracing the junction between said leg portion and said footing plate.

5. As an article of manufacture, an integral derrick leg unit comprising: a derrick leg portion having an L shaped cross-section and terminating at one end in a footing plate integral with said leg portion and disposed at such an angle to said leg portion as to place said footing plate in a substantially horizontal position to act as a footing member for said leg portion when said leg portion is installed on a derrick; and a pair of bracing plates integral with said leg portion and said footing plate, each of said bracing plates lying substantially in the plane of one of the arms of said L shape for bracing the junction between said leg portion and said footing plate, and each of said bracing plates having portions disposed at right angles to the plane of said footing plate for attachment to perimetric members.

AARON D. RHODES. 

